Drying and roasting furnace.



PATENTED OCT. 17,19%;

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C. E BALLOW la E STEIN.

DRYING AND ROASTING IEURLMIEa APPLICATION FILED MAR-.15, 1905.

No. 802,191. PATENTED OCT. 17, 1905. C. E. BALLOW 6L E. STEIN.

DRYING AND ROASTING FURNAGE.

APPLICATION FILED MAR.15,1905.

3 SHBETS-SHBE'T 2.

TE STATES PATENT UEETCE.

DFEYING IND ROASTING FUFINGE.

Specification of Letters Patent.

Patented Oct. 17, 1905.

Application filed March 15, 1905. Serial No. 250,190.

To @ZZ whom t 'may concern/ Beit known that we, CnAELEs E. BALLow and ERNEST STEIN, citizens of the United States, and residents of Guanaeevi, State of Durango, Mexico, have invented a new and Improved Drying and Roasting Furnace, of which the following is a full, clear, and exact description. A

The invention relates to a furnace for dry- `ing and roasting ores, and it resides particularly in a peculiar combination of a drying and roasting furnace7 so that the two may be coactivelyl operated, producing better results than heretofore. i i

The invention also relates to peculiar devices for agitating the ore as it passes through the furnaces, these devices consisting of the combination of shelves and rollers which thoroughly work the ore and retardits downward movement sufficiently to enable the necessary drying and roasting operations.

The invention also relates to certain other features of major or minor importance, all of which will be fully set forth hereinafter and particularly pointed out in the claims.

Reference is had to the accompanying drawings, which illustrate as an example the preferred embodiment of our invention, in which drawings like characters of reference indicate like parts in the several views, and in. which- Figure 1 is a side elevation of the furnace. Eig. 2 is a vertical section thereof on the line 2 2 of Eig. l, and Eig. 3 is a vertical section taken across the line of section in Eig. 2 and through the drying-stack.

The furnace is constructed of a material.

suitable to the purpose and is provided with a drying-stack 10, at the base of which is an auxiliary furnace 11, and opposite the furnace is a passage 12, communicating with a downtake -flue 14. This flue 14 extends from the top of the roasting-stack 1 5, and at the base of said stack is a main furnace 16.

17 indicates the" escape to the atmosphere from the drying-stack, and 1S and 19 indicate, respectively, charging-orifices for the roasting and drying stacks.

20 indicates the outlet from the dryingstack, and 21 the outlet from the roastingstack.

The furnaces 11 and 16 are preferably located at the bases of their respective stacks; but they may be located at any desired elevation along the stack as the peculiar nature of the work for which the furnace is intended may require.

In the use of the furnace the ore to be dried is charged into the stack 10 through the orifree 18 and is heated ordinarily by the waste gases passing from the roasting-stack by way of the downtake-flue 14 and passage 12. If the nature of the ores be such as to require an excessive drying-heat, a fire may be built in the furnace 1.1 to reinforce the waste heat derived from the roasting-stack. After the ore is dried in the stack 10 it may be with.- drawn through the discharge 20, whereupon it may be crushed by any suitable apparatus (not shown) and charged back into the furnace by the opening 19, it then passing down through the roasting-stack and the finished product of the furnace passing out through the outlet 21. This peculiar arrangement of the roasting and drying stacks is important, since not only does it utilize the waste heat from the roasting-stack and enable the drying operation to be performed far .more economically than ordinarily, but it also enables us to save a large percentage of the volatile metals ordinarily passed off in the waste gases of the roastingffurnace. In our invention the volatile metals passing through. the drying-stack in vapor form are deposited on the sides of the stack upon the agitating devices therein, as will be hereinafter fully described,` and upon the ore itself. Such portions of the volatile metals as are deposited on the Walls of the stack and on the agitating devices thereof subsequently attach themselves to the ore passing through the drying-stack and may be savedxin the subsequent smelting or reducing processes.

In each stack we arrange a number of agitating-rolls 22, which. are horizontally disposed one above the other and are corrugated, as shown; but, if found desirable in practice, said rolls may be plain. Between the rolls are located horizontal shelves 24, which project from the walls inward toward the ccnters of the stacks. The ores in falling through the stacks are engaged by the rolls and shelves and are agitated thoroughly as they fall from one to the other. The rolls may be rotated or not, as desired; but in most classes of work rotation is preferable, and this may be continuous or intermittent, as the work requires. For rotating the rolls any desired TOO mechanism may be provided. llfe have here illustrated pulleys 25 attached to the shafts 26 of the rolls and having belts 27 run over them, as shown best in Fig. 1. These belts are connected with any suitable mechanism (indicated at 28) for driving them. Y rlhe walls of the stacks are provided with staggered openings 29, through which the rolls may be withdrawn for repairs, and 30 indicates any desired means for closing these openings during the operation of the furnace. ln order to prevent the excessive heating of the rolls, and consequentlT the premature destruction thereof, we provide, preferably, the lower roller, but, if desired, all of the rolls, with tubular axial shafts into which water or other cooling Huid is charged from pipes 31, the water being discharged from the opposite ends of the tubular shafts into collecting devices 32. By this circulation of water the rolls are kept at a proper temperature.

The manner of using the furnace will be understood from the foregoing description, taken in connection with the drawings, by persons skilled in the art. It will also be understood that the operation of the furnace and the manipulation of the ores therein and with respect thereto will be widely varied, according to the nature of the ores and the results to be produced, and these variations will suggest themselves instantly to skilled metallurgists. A detailed description of these various operations is, therefore, not necessary here.

It is pointed out that the furnace may be used with but one stack, if desired. For instance, the stack 10 may be used and the stack 15 and flue 14 dispensed with.

Having thus described our invention, we claim as new and desire to secure by Letters Patent# 1. A furnace provided with a drying-stack, a roasting-stack, means for conducting the waste gases from the top of the roastingstack to the bottom of the drying-stack, and means for heating the roasting-stack.

2. A furnace provided with a drying-stack, a roasting-stack, means for conducting the waste gases from the roasting-stack to the drying-stack, means for heating the roasting-stack, and auxiliary means for heating the drying-stack.

3. A furnace provided with adrying-stack, a roasting-stack, a downtake flue leading from the top of the roasting-stack to the base of the drying-stack, and means for heating the roasting-stack.

4. A furnace provided with adrying-stack, a roasting-stack, a downtake flue leading from the top of the roasting-stack to the base of the drying-stack, means for heating the roasting-stack, and an auxiliary means for heating the drying-stack.

5. A furnace provided with a drying-stack, a roasting-stack, a means for transferring the waste gases from the roasting-stack to the drying-stack, and a furnace proper at the base of the roasting-stack.

6. A furnace provided with a drying-stack, a roasting-stack, a means for transferring the waste gases from the roasting-stack to the drying-stack, a furnace proper at the base of the roasting-stack, and an auxiliary furnace proper at the base of the drying-stack.

7. A furnace provided with an ore-roasting means, an ore-drying means, means for transferring the waste gases from the roasting means to the drying means, and a furnace communicating with the roasting means to introduce gases of combustion into the same.

8. A furnace provided with an ore-roasting means, an ore-drying means, means for transferring the waste gases from the roasting means to the drying means, a furnace communicating with the roasting means, and an auxiliary furnace communicating with the drying means.

9. A furnace provided with a drying-stack having a discharge into the atmosphere at its upper end and an ore-discharge at itslower end, a roasting-stack having an ore-discharge at its lower end, a downtake-flue passing from the top of the roasting-stack to the base of the drying-stack, and means for heating the roasting-stack.

10. A furnace provided with a dryingstack having a discharge into the atmosphere at its upper end and an ore-discharge at its lower end, a roasting-stack having an ore-discharge at its lower end, a downtakeflue passing from the top of the roastingstack to the base of the drying-stack, means for heating the roasting-stack, and an auxiliary heating means at the base of the drying-stack.

1 1. A furnace having a stack, an agitatingroll located therein, a tubular axial shaft mounting said roll, and means for passing a cooling medium through said shaft.

12. A furnace having a stack, an agitatingroll mounted therein, a tubular axial shaft for said roll, means for introducing a cooling medium into one end of the shaft, and means for carrying off the cooling medium from the other end of the shaft.

13. A furnace having a stack with an opening in one side thereof, an agitating-roll located within the stack, and means for mounting the roll, said roll being withdrawable from the stack through the said opening in the wall thereof.

14. A furnace provided with a dryingstack having a discharge into the atmosphere at its upper end, and an ore-discharge at its lower end, a roasting-stack having an ore-discharge at its lower end, a downtakefiue passing from the top of the stack to the base of the drying-stack, means for heating the roasting stack, an auxiliary heating IIO means at the base ofthe drying-stacl agitating-rollers mounted in said roasting and dry ing stacks, means for operating the rollers7 and shelves carried by the stacks and proj eoting into the same between the rollers, Jfor the purpose specified.

l5. A furnace provided with a drying stack having a discharge into the atmosphere at the upper end, and an ore-discharge at its lower end, a roastingstaek having an ore-discharge at its lower end, a downtakelue passing from the top of the roastingstaol to the base of the drying-stack, means for heating the roasting-stack, an auxiliary heating means at the base of the dryingstack, corrugated agitating-rollers mounted in the drying and roasting stacks7 and shelves carried in said stacks and projecting between the rollers, certain of the rollers having tubular axles projecting through the walls of zo 

